Unpleasant sister in law, help please

I think I’d give a kind but sorrowful sort of smile, and say, ‘I’m afraid you must be very insecure if you must keep saying such things every time I see you. Have you thought of seeking professional help?’

But then I wouldn’t mind being a bit 😈 to such a person.

repeat back to her what she has said as though you did not understand.

That sounds like a good idea.

She sounds ridiculous. We're working folk, no idea anyone cared.

But playing off that, perhaps ask her opinion to starting a housekeeping or gardening service as a way for people to work with the economy as it is?

You could then talk on about the economy, COL, benefits, anything but yourself. She's not clever if her fall back is being nasty about height, so you be the clever one and talk about newsworthy things.

Nobody has to attend a family event, if it bothers you that much don't go.

If you are going to attend then just stay away from her, if she says anything to you look at her without saying anything for a couple of seconds or repeat back to her what she has said as though you did not understand.

Lollypolly you are obviously a far nicer person than me. I would have told her long ago to duck off! It of course isn't too late.

The old favourite ‘did you mean to be so rude’ might work,
Otherwise keep away from her if you can.
I have a difficult sil too, it’s been awkward but luckily we don’t meet up now.
See it as her problem not yours.

It does sound like jealousy Lollypolly. The best way to deal with this is to let it wash over you. Don't respond, try changing the subject and if that doesn't work, smile and walk away.

Just say “sour grapes?” And walk away.

You don’t have to stand there and listen to her being nasty to you.

She's jealous of you.